Eric, thank you for the list and your reply.
Using this list and cross-referencing with a 1960 sales brochure for mine (which is a Series IIIb by birthdate but has some trivial IIIc items on it such as the plastic access covers for oiling the door latches….) I can estimate that I have "Regency Beige" over "Caramel" with an optional Scarlet Red interior.
However my question still is where on the car did Rootes place the single/double digit codes for the paint? If it was on a paper decal (like some of the Aussie Rootes sites show), then it may be missing due to age. I figured it might have been stamped somewhere but haven’t come across it.